International safety standards often specify maximum surface temperatures in engine environments. One component of the engine environment is the exhaust manifold, which accumulates exhaust gases from multiple engine cylinders into one exhaust pipe. In the marine environment, jacket-cooling is a method used to comply with safety standards specifying maximum surface temperatures. A coolant jacket can shield and cool hot exhaust manifolds coupled with an engine, thus maintaining a surface temperature below the specified maximum. Such jacket cooled exhaust manifolds can be constructed out of fabricated or cast metal.
Prior exhaust manifolds, such as the exhaust manifold disclosed in U.S. Pat. No. 3,921,398 to Kashmerick, have portions constructed out of cast aluminum and include a cooling jacket to reduce the surface temperature of the exhaust manifold. The prior casting methods used to construct such exhaust manifolds required a complex and a resource intensive manufacturing process, often requiring casting of multiple pieces followed by an assembly of cast portions. The present disclosure is directed to mitigating or eliminating one or more of the drawbacks discussed above.